This invention generally relates to vehicle electronic throttle controls. More particularly, this invention relates to a return spring mechanism for an electronic throttle control assembly.
Vehicle throttle control assemblies typically include a throttle body having an air inlet. A blade portion typically is positioned within the inlet and manipulated to control the amount of air flow. Conventional arrangements included springs and linkages for controlling the position of the blade portion responsive to movement of the accelerator pedal.
More recently, electronic throttle control assemblies that replace the mechanical linkages and springs with an electrically powered arrangement have been introduced. An electric motor provides the motive force to move the blade among various positions within the inlet to control air flow. The electric motor receives signals from a controller that generates command signals based upon the driver""s activation of the accelerator pedal.
One challenge associated with an electronically controlled throttle assembly is addressing situations where the electric motor stops operating properly or there is some malfunction in communicating control signals or power to the motor. The electric motor arrangement does not include any mechanism for automatically returning the throttle blade to a closed position to prevent the motor from running at an undesirably high rate when the driver does not manipulate the accelerator pedal. Additionally, there is no ability to move the blade from a fully closed position, which would be desirable to be able to move the vehicle to a service location, for example.
Accordingly, there is a need for a device to control the position of the throttle assembly components even when the electric motor is not operating as intended. This invention addresses that need.
In general terms, this invention is an electronic throttle assembly for a vehicle with an automated, mechanical return mechanism to control the position of the throttle assembly components. The inventive arrangement includes a throttle housing having an air inlet opening. A blade portion is supported within the opening. An electric motor selectively moves the blade between a plurality of positions within the opening. A position controlling device includes a generally arcuate spring that biases the blade portion into a home position.
In a preferred embodiment, the home position permits some air flow into the opening to permit the vehicle to be driven to a service location, for example. The position controlling device preferably includes an arcuate spring. One end of the spring engages a plate portion that is associated with the shaft that supports the blade within the air inlet. The resting position of the spring preferably biases the blade portion into the slightly opened, home position.
The various features and advances of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawing that accompany the detailed description can be briefly described as follows.